Grantee: Vets4welfare

Institution: Vets4welfare Foundation, Netherlands

Grant amount: $20,000

Grant type: Small grants

Focal species: Crab-eating macaque (Macaca fascicularis)

Conservation status: Endangered

Disciplines: Physiology, wildlife rehabilitation, human-wildlife conflict

Research location: Indonesia, Netherlands

Project summary

This project will compare cortisol concentrations in the hair of Indonesian monkeys (Macaca fascicularis) from three groups: a group whose members have spent their whole lives in the wild, a group that has been kept in captivity for the entertainment industry, and a group that are in the process of rehabilitation following rescue from the entertainment industry. Hair measurements can reflect welfare over a long period, as they integrate cortisol as they slowly grow. The concentration of cortisol in a segment of a hair is thought to reflect the activity of the animal’s physiological stress response at the time that segment was produced. On that premise, the project aims to compare the stress response of M. fascicularis under wild, poor-welfare captive (entertainment), and high-welfare captive (rehabilitation) environments. The hair cortisol data will be compared with veterinary and forensic records and other welfare-relevant observations (e.g., of infections or injuries) where possible. The researchers also intend to determine whether mistreatment in captivity leaves a signal in hair cortisol that could be detected after the fact and used to identify monkeys that have been illegally trafficked. 

Why we funded this project

Although this project focuses narrowly on anthropogenic harms in a particular threatened species, we funded it because their approach is interesting and very similar to one we have been interested in applying to study the welfare of stocked fish (i.e., fish raised in a hatchery and then released into the wild) using biological aging methods, another category of putative welfare indicators that integrate stress over time. Between these two funded studies, we are interested to see 1) how welfare indicators for wild and captive environments of varying quality compare and 2) whether hair cortisol from individuals whose environment changed is consistent (at the corresponding points in time) with that of individuals who were only exposed to one environment or the other. We anticipate that the relationship for the latter question is more complex than described, but investigating it will help us learn more about the validity of hair cortisol measurements and the importance of prior experiences in shaping animals’ stress responses.

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